[VitisAI] custom op support multiple outputs (#21280)
### Description
The implementation inside EP requires registering some custom ops which are only used in the model compilation phase. Currently only single output is supported.
### Motivation and Context
Now the demand upgrade requires support for multiple outputs, so the shaper infer of ep custom op needs to be extended to support multiple outputs
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Co-authored-by: liumingyue <mingyue@xilinx.com>
Co-authored-by: mingyue <mingyue@amd.com>
